Polarization and TMDs: recent results on Sivers function extraction

The partonic Sivers function is fundamental to understand the effect of polarization on the internal 3D structure of nucleons, as it encodes the correlation between the intrinsic transverse momentum of partons and the transverse spin of a polarized nucleon. Its study provides essential insight into the three-dimensional momentum structure of the nucleon and the role of parton orbital angular momentum in the origin of nucleon spin. However, being a non-perturbative object it cannot be directly calculated but has to be determined through statistical fits on experimental measurements.
We will discuss the theoretical framework and the methods necessary to determine this polarized distribution. 
Finally, we present some preliminary results on its most updated extraction, through a global fit of SIDIS and DY datasets, performed within the fully consistent "MAP" framework.